Surprised Magic Initiate isn’t more popular.
I see it mostly on Variant Humans taken as their free Level 1 feat... And not much on others.
Ritual Caster (Wizard) seems to be more popular, from what I can tell.
Spell Sniper seems to be even more popular, especially Spell Sniper (Warlock) for Sorcerers and sometimes Bards/Paladins to get Eldritch Blast plus doubled attack spell range and ignored cover.
That last one is reflected in the above DnDBeyond stats.... In DnDBeyond, the feat is coded as "Spell Sniper (Bard, Sorcerer, Warlock)". In the stats chart, they've just shortened it to "Spell Sniper (Bard)", but "Spell Sniper (Warlock)" would almost certainly be more accurate for its most common use. (Bards don't even have an eligible attack cantrip on their spell list that can be taken with Spell Sniper anyway...)
I continue to be baffled by why so many Monks take Mobile.
It may not seem like it's worthwhile on paper, but trust me, it works very well in practice. (Especially in Tier 1 and lower Tier 2 play, where most D&D takes places.)
Free Disengage is a powerful tool for Strikers like Monks and Rogues, provided there's one or more Tanks to hold the front line. If there's one or more Tanks in the party, especially if they're augmented by additional "stickiness" from stuff like the Conquest Paladin's immobilization or the Sentinel feat, then Monks and Rogues can flit in and out of combat to get their hits in without lingering on the front lines, and monsters have more difficulty pursuing them past the front line of tanks on their turn.
And extra movement is always nice, especially on an already ridiculously fast class like a Monk.
Dodging costs Bonus Action and Ki. Disengaging usually costs Bonus Action and Ki. But Mobile allows you to Disengage for free. And still having the Bonus Action Dodge as another option is nice. Nothing says you always have to Disengage, or you always have to Dodge. There are situations in which you'll want to stick around and Dodge, but typically more situations in which you'll want to Disengage from the front lines.
Stun is an especially great ability, but it also costs Ki. And you won't want to be burning Ki on it in every encounter. You especially don't want to be burning 3-4 Ki points in one round to Stun the Big Bad as well as his several minions milling around. And Stun isn't guaranteed. The attack may not hit, and the Stun may not stick.
Whereas Mobile works even if your only attempt an attack. Hitting/Missing/Save DC doesn't affect Mobile's Disengage. So you can run in, stun the toughest bad guy with an attack or two, toss a couple attacks or even stun attempts at the other mooks around him that are threatening you with OAs, then duck back out. Even if every single one of your attacks that round miss, or the Stuns don't stick, you're still able to freely Disengage.
Also, Stun doesn't come online until Level 5, and even once it does, your Ki is very limited at Level 5ish. Keep in mind that most play is at lower levels, where Stun either isn't available, or is used sparingly due to minimal Ki and significant competition for that minimal Ki.
+2 to Dex or Wis for a Monk is a huge deal.
On that we agree.
Mobile is most noticeably great on Variant Human Monks at lower levels. But it's still useful on higher level Monks. However, you're right that you usually wouldn't prioritize it over bumping DEX or WIS, especially if either one or both are still at 14/16ish.